120gr. GMX load

[coyotetan]

Anybody has a good load for 120gr. gmx ? Here in CA we have to use leadfree bullet in the condor zone and pretty soon it will be leadfree statewide. I have a BHW 20" barrel with 8 twist, shoots sub moa with 123 gr. amx, just couldn't find a good load the 120 gr. gmx, did a search here and came up empty.

[sneaky one]

Hornady has the load data. It's lethargic in a short case, not enuff speeds.

Check - for starters the recent 220 lb. hog down using experimental 94 grn. GMX- from DN SPY. You tube vid. attached.

Hunting section.

Next, check my albums, & More. Click on Ahnold- scroll down.

Check my trials since 2010. Most pics have data under the pic. The length , vs. wt. is fine for a .260 Creed , or Rem.

Grrr is a short case. I adapted. Look at my hunt post from last November. 280 lb. Big deer down- 77 GMX. 21 yds. Smoked!

I tweaked them all. 120's won't expand enuff as is in the grrr past 75 yds.

Then more searches as to what I have found to work well with GMX pills.
And the Barnes units.

Copper is coming on strong as the Only choice for hunts- we have to adapt. The inclusion of 5% zinc - makes barnes look weaker. Gilding metal rocks.

I have had a small amount of engineering help on this- the rest was from my past experiances. It works.

[LRRPF52]

You could also try the 120gr TSX. That's a known performer and readily available.

Same for the 100gr TTSX, or one of the Lehigh Defense bullets.

Load data is available here on the site, as well as the 6.5 Grendel Reloading Handbooks for your bench.

[diddlyv]

Anyone loading the 120 GMX have good COL. Seated mine at 2.247 and they hit rifling and need to be rodded out. Going to bump a little deeper in the case obviously. Have barrel of unknown origin and too cheap to buy the bullet seating checking equipment.

[sneaky one]

didd , there's a few versions of the Gmx out there. Some, the older units- I loaded mine to 2.31. I tweaked a mag. to run to 2.33 oal. extra space for powder.

In my AA tube, rifling contact was made @ 2.360- so I ended up with a 50 k jump, instead of 100k. Very accurate bullet.

2 years ago- Rickoshay and I were testing Gmx, he called me and asked if I checked my bullets before loading. Wait! Huh?

He had a few I sent him, that could barely be seated @ 2.26oal. I checked my rounds- no fit! I pushed bullets in deeper,-- flatter primers.

It pays to get some equipment. And check everything, I tend to be on cruise control when loading. Now I check every 1 before I load them- then categorize by length.

And adjust the powder charge accordingly. So it's hard to tell if you have a Sammie chamber with this bullet, as a component.

Major ammo companies do QC, and do the best to make safe ammo for us. Us loaders have to do our own checks.

[diddlyv]

didd , there's a few versions of the Gmx out there. Some, the older units- I loaded mine to 2.31. I tweaked a mag. to run to 2.33 oal. extra space for powder.

In my AA tube, rifling contact was made @ 2.360- so I ended up with a 50 k jump, instead of 100k. Very accurate bullet.

2 years ago- Rickoshay and I were testing Gmx, he called me and asked if I checked my bullets before loading. Wait! Huh?

He had a few I sent him, that could barely be seated @ 2.26oal. I checked my rounds- no fit! I pushed bullets in deeper,-- flatter primers.

It pays to get some equipment. And check everything, I tend to be on cruise control when loading. Now I check every 1 before I load them- then categorize by length.

And adjust the powder charge accordingly. So it's hard to tell if you have a Sammie chamber with this bullet, as a component.

Major ammo companies do QC, and do the best to make safe ammo for us. Us loaders have to do our own checks.

I do use a caliper, but do lack the ability to measure chamber length to rifling. So do the old fashion chamber round look at bullet for marking kind of thing.
As to the GMX, they are what midway sent last week, hoping the latest version

[diddlyv]

I acquired the Loc N Load Bullet comparator, 6.5 Bushing and 6.5 Headspace Bushing (among a truck ton of others) and the associated modified cases. Can now deal quasi intelligently with loading the grendel.

[sneaky one]

Enjoy your findings didd. Follow known data- to see where you end up, for speeds.

[diddlyv]

Thanks

Actually pretty conservative, when it comes to loads. The distance between holes on targets more important than super velocity.

If I need a 130 grain bullet to go 2700 fps, my 6.5 creedmore does that easily,

[coyotetan]

After some experiments, I've found a decent load for my particular rifle, I am shooting a 20" BHW barrel, with 27.50 gr. of IMR 8208, I am getting 1" group at 100 yard, I seated bullet at 2.670 ( measured with Hornady bullet comparator), average velocity is 2481, SD: 5, ES: 11.

I am going to try to seat a little deeper and see if it will get better group

[sneaky one]

You may want to gel, or water jug test the expansions- results- , before hunting anything, bigger than a coyote. The pill does open, yet to marginal effect at lower speeds.

More impact speed is needed for whitetail class sized game. My 77 GRN GMX took down a mighty 280 lb. buck last November.

The 120 Gmx- will produce a decent kill, in a CNS - shot- or a head shot. It's just so pokey...

[diddlyv]

Well came off the dime for the bullet comparator OAL bushings and the Headspace bushings. I determined the problem with the GMX was not the bullet but the .295 neck would stick if there was a burr on the case mouth. This only occurred with new brass. If I trimmed to the trim to length and deburred there was not a problem. On new brass if I crimped SSTs ever so slightly problem went away. Both my Grendel barrels have the 264 LBC chamber. I may be a heretic but I can live with that. Pretty much anything that will fit in the Magazine will not be jammed into the lands. Think I will try the 2.260 length for the 120 GMX. I only bought 50 of them. If I cannot get them to shoot well I won't buy anymore. I may try the Lehigh Defense 95 grainers.

Essentially I was looking for a hog busting load. The 5.56 hog buster of the week remington, hornady etc is using copper bullets, was applying that logic to the grendel. Pretty sure the 123 SST might do the job just fine.

[ricsmall]

Diddy

If looking for a hog busting load, and shots may often be less than ideal, I would go with the 100 ttsx. We've shot 11 hogs in the past month here on the place and 4 have left the county toting 123 sst's with them. They are great bullets, but on these tough pigs your gonna want either mono pills or fmj. In talking with most guys around here that are successful, fmj pills are serving better when shot placement isn't optimal. I've killed a ton of pigs with 62gr TSX in a .223, most were shoulder shots and all but a few dropped drt.

Richard

[diddlyv]

Thanks for the tip, if I cannot get the last 24 GMXs in the box to fly, I may well invest in a box of the 100 TTsx and perhaps the 95 grain lehigh defense. or even the 118 grain hollow basers in another thread. New rifles, new calibers, new bullets wow, the reloading bench just got more intersting than x number of grains of varget under a 175 sierra or y grains under a 155 palma from my high power days. Pretty much quit shooting the 168 grainers once the Palma and 175 grainer hit the street.

[Bisley]

If you knew the REAL story behind what they did to CA hunters, you would (hopefully) NEVER buy another TTSX bullet again so long as you live!